JP2012500719A - Parallel jet loop reactor - Google Patents

Abstract

  The present invention relates to an apparatus and method for continuously reacting a liquid with at least one second fluid, the apparatus comprising at least two jet loop reactors connected in parallel to each other; And one common external liquid circuit.

Description

  The present invention relates to an apparatus for continuously reacting a liquid with at least one other fluid.

  A liquid is a fluid medium that is substantially incompressible. Gas is a compressible fluid medium. The fluid is a liquid or a gas. In particular, a pulverulent solid which has been fluidized with a gas or liquid is also a fluid in the sense of the present invention.

  Within the scope of the present invention, the supplied liquid means a substance or mixed substance which is in a liquid agglomerated state under reaction conditions in the apparatus and has at least one reactant. By gas is meant a pure gas or gas mixture having at least one reactant and optionally an inert gas. An example of a gas having two reactants is a synthesis gas consisting of hydrogen and carbon monoxide, for example used in hydroformylation.

  In the present invention, a jet loop reactor (in English) is a device for continuously reacting a liquid with at least one other fluid, in which the liquid causes a nozzle under pressure. Enters the reaction chamber, flows through the reaction chamber in the main flow direction, is turned at the end of the reaction chamber located on the opposite side of the nozzle, is returned to the main flow direction, and is again in the main flow direction. It is accelerated by. Thereby, an internal liquid circulation path (loop) is formed inside the reaction chamber. The second fluid is entrained by the liquid flow and reacts in a path along the loop. The liquid thus acts as a driving jet medium. In order to put kinetic energy into the liquid, an external liquid circulation path is assigned to the reaction chamber, and in the external liquid circulation path, a part of the liquid is guided in the circulation path outside the reaction chamber. A pump is provided in the external liquid circuit, which provides the liquid flow with the kinetic energy necessary to form a loop flow inside the reactor. Correspondingly, the nozzle is fed from an external circuit. A known jet loop reactor is shown in FIGS. 1a and 1b.

  "Bubble Columns" (by P.Zehner, M. Krause) of Ullmann's Encyclopedia of Industrial Chemistry (Electronic Release, 7th ed., Chapter 4, Wiley-VCH, Weinheim [2005]) is an introduction to jet loop reactor technology. Ideal for.

In order to effectively perform multiphase reactions in a gas / liquid system or gas / liquid / liquid system, it is important to intensively mix the phases involved in order to avoid mass transfer limitations. Technically, this is achieved by a wide variety of reactor concepts, starting with stirred tanks and going into tube reactors with bubble and packed towers and fixed mixers (K. Schuegerl ; "Neue Bioreaktoren fuer aerobe Prozesse"; Chem.-ing.-Tech.52, (12), 1980, 951-965). The disadvantage of these systems is in part due to the relatively low capacitive mass transfer coefficient (k _L a).

  A wide variety of reactor concepts have been improved to improve mass transfer, especially in multiphase catalysts. Their common feature is high circulation (see E. H. Stitt; "Alternative multiphase reactors for fine chemicals-A world beyond stirred tanks?" Chem. Eng. J. 90, 2002. 47-60). This creates the necessary mass exchange area via a suitable mixing device such as a nozzle or a restriction. Special reactors based on multi-component nozzles have already been tested in detail (N. Raebiger; “Hydrodynamik und Stoffaustausch in strahlangetriebenen Schlaufenreaktoren”; Praxiswissen Verfahrenstechnik: Thermische Verfahrenstechnik, Verlag TUEV Rheinland GmbH, Koeln, 1988 36, Koeln, 1988 36). Are effectively used in test equipment for hydroformylation. This reactor is characterized by a high space time yield and a high mass transfer rate between the gas and liquid phases. Furthermore, since the unreacted gas is dispersed again into the liquid via the nozzles in the reactor, the circulating compressor normally required for gas return guidance is omitted. The gas content in the reactor can be freely selected depending on the filling level and the relative position of the gas inlet of the nozzle. Therefore, it is not necessary to adjust the filling level. In addition, the large recirculation flow that occurs inside the reactor results in an almost gradient-free operating mode.

  In this case, in the individual jet loop reactors, the height-diameter ratio can only be changed within a narrow range of 3-10 in order to ensure a sufficient reaction volume under reliable reactor configuration height. Mixing ratio and mass transfer are negatively affected in dense configurations. This can only be offset by placing multiple nozzles and conduits in one reactor (Y. Gan et al .; "Studies on configuration of jet loop reactors with low height-diameter ratio"; Chem. Reac. Eng. Tech. 15 (3), 1999, 268-274). Furthermore, the heat derivation is further exacerbated by the small surface area / volume ratio. This requires the use of field tubes inside the reactor, as described in DE 19854637, in order to increase the heat exchange area. This not only impairs the internal circulation, but also increases the structural effort.

  Aspect ratio (ratio of reactor height H to reactor diameter D) H: D> 10 allows for relatively high gas content, but small volume makes it suitable for scale-up Not. Based on the resulting reactor height, when the reactor is scaled to the associated reaction volume, the internal pressure loss increases, thus resulting in excessively high energy dissipation that significantly degrades the reactor output. However, due to the small diameter, in this case sufficient heat exchange efficiency can be obtained without additional equipment.

  Based on the above disadvantages of known reactors, the object of the present invention is to provide a reactor or reactor apparatus for continuous fluid-liquid reactions with a suitable efficiency profile.

  This problem is solved by the device according to claim 1.

  The present invention provides an advantage of a jet loop reactor for high product capacity when a liquid is continuously reacted with another fluid by a parallel connected jet loop reactor having a common external circuit. It is based on the recognition that it can also be used.

  The subject of the present invention is therefore an apparatus for continuously reacting a liquid with another fluid, comprising at least two jet loop reactors connected in parallel to each other and a common external liquid circuit. is there.

  The subject of the invention is also a method for continuously reacting a liquid with another fluid, in the device according to the invention, reacting at least one gaseous reactant with at least one liquid reactant. Is.

  The advantage of the device according to the invention is that the advantages of the jet loop reactor, such as intensive mass transfer, high heat extraction or introduction, and operation mode with almost no gradient, can be exploited for large product volumes.

  Since this device has only one pump to maintain an external circuit, capital and operating costs are higher than in the case of a device consisting of at least two jet loop reactors each with its own external circuit. It does not take. Thus, in an advantageous configuration, only one pump is arranged in the external liquid circuit.

  In a particularly advantageous configuration of the invention, each nozzle is assigned a lead-out for the liquid, the nozzle and the outlet being arranged in diameter in the reactor with respect to the internal liquid circuit, An external liquid circuit connects the nozzle to the outflow. Such an alternative configuration provides an excellent flow profile.

  The common external liquid circuit is advantageously provided with a heat exchanger in the external liquid circuit for the exchange of heat between the liquid guided in the external liquid circuit and the heat transfer medium. Yes. The internal heat exchanger can therefore be omitted, which improves the flow inside the reactor. The introduction or derivation of the heat of reaction is particularly effective.

  The device according to the invention is suitable for reacting a liquid (as drive medium) with at least one other fluid. However, it is possible to react two or more fluids other than the drive medium. Therefore, the following two-phase reaction is feasible.

Liquid / Liquid Liquid / Gas The three phase reaction can be carried out as follows.

Liquid / Liquid / Liquid Liquid / Liquid / Gas Liquid / Gas / Gas An example of the device according to the invention and the method according to the invention carried out by the device according to the invention is described below.

FIG. 1 shows a jet loop reactor with a nozzle above (prior art). FIG. 1 shows a jet loop reactor having a nozzle below (prior art). FIG. 2 shows a circuit diagram of a jet loop reactor according to the present invention. It is a figure which shows the parallel structure of the jet loop reactor formed as a tube bundle type | mold which has a nozzle above. It is a figure which shows the parallel structure of the jet loop reactor formed as a tube bundle type | mold which has a nozzle below. 1 is a diagram showing a test apparatus of Example 1. FIG. FIG. 6 is a diagram showing a test apparatus of Example 2.

  An apparatus according to the invention for carrying out a reaction in which a liquid is continuously reacted in parallel with another fluid consists mainly of two or more jet-loop reactors connected in parallel with these reactors. Have one common external liquid circuit.

  A conventional jet loop reactor is shown in FIG. 1a. In this jet loop reactor, the jet nozzle is located in the upper part of the reactor and the starting material is fed into the upper part of the reactor. The reactor consists of a pressure tube incorporating a nozzle (1), a conduit (2) and an impingement plate (3). The reactor has a heating / cooling jacket (4). Further, a valve for taking out the exhaust gas for discharging the inert gas component may be incorporated in the gas chamber above the reactor (not shown in FIG. 1a).

  The conduit is advantageously arranged concentrically with the jet nozzle and the pressure tube. In this case, the jet nozzle may be a single-component nozzle or a multi-component nozzle, and in another configuration, the jet nozzle may be further provided with a pulse exchange tube and / or a diffuser. During operation, the nozzle sinks completely or partially into the liquid reaction medium, and the sinking depth may correspond to a plurality of conduit diameters. The conduit has a diameter of 1/10 to 1/2 of the reactor diameter and extends approximately the entire length of the reactor. The conduit is limited by the impingement plate at a suitable distance downward and the upper end is located below the liquid surface during operation. The reactor is characterized in that only a small part of the liquid is fed again into the nozzle via the external circulation due to the high circulation flow inside.

  In the apparatus according to the invention, the jet loop reactor used has a high aspect ratio (ratio of reactor height H to reactor diameter D). The aspect ratio is in the range of 5-15, preferably in the range of 8-12, particularly preferably in the range of 10-12.

  Based on the high aspect ratio, the assembly of the internal heat exchanger can be omitted. This is because heat can be sufficiently introduced and discharged through the jacket surface and through the heat exchanger in the external circulation path.

  In another configuration shown in FIG. 1b, the nozzle (1) can be located at the bottom of the reactor. The conduit (2) is in this case advantageously arranged concentrically with respect to the jet nozzle and the pressure body, which jet nozzle can be configured as a single or multiple nozzle. The gas supply is performed under pressure. In an advantageous configuration, the gas suction is performed automatically by the discharge operation of the nozzle. The conduit (2) has a diameter of 1/10 to 8/10, preferably 4/10 to 7/10, of the diameter of the reactor and extends almost the entire length of the reactor. In this case, the upper end is positioned below the liquid surface during operation. The reactor has a relatively high internal circulation and only a small part of the liquid is fed again to the nozzle via the external circulation.

  The device according to the invention consists of at least two reactors. The number of reactors is preferably in the range 2-20, particularly preferably in the range 2-14.

  The reactors can be different or advantageously the same.

  FIG. 2 shows an example of a device according to the invention, which comprises three reactors connected in parallel to each other, a circulation pump and a heat exchanger provided in a common external liquid circuit. The starting material is fed to the upper reaction chamber. A conduit for removing the exhaust gas from the upper part of the reactor is not shown. In this drawing, a cooling circuit or a heating circuit is shown. However, each heat exchanger can also be operated separately.

  As shown in FIG. 3, the individual reactors can be combined into one bundle. The tube bundle reactor consists of at least two individual reactors. One tube bundle preferably has 3 to 14 individual reactors. In a tube bundle reactor, the individual partial reactors preferably have the same design.

  The apparatus according to the present invention may comprise one or more tube bundle reactors, or at least two individual reactors, or a combination of one or more tube bundle reactors and one or more individual reactors.

In the device according to the invention, as described above, the nozzles can be arranged in various ways in the reactor.
a) In all reactors, the nozzle is located in the upper part of the reactor (FIG. 3a).
b) In all reactors, the nozzle is located in the lower part of the reactor (FIG. 3b).
c) In the reactor, at least one nozzle is incorporated in the lower part of the reactor and at least one nozzle is incorporated in the upper part of the reactor (not shown).

  In all configurations shown, the nozzle outlet for the drive jet is below the liquid level.

  The device according to the invention is used inter alia for the reaction of liquids and gases. In this case, both the gas and the liquid have at least one reactant.

  In addition, a liquid in which the catalyst is homogeneously dissolved, or a liquid contained in a suspended state under the condition that the average particle size of the catalyst is smaller than 200 μm, particularly preferably smaller than 100 μm, is used. You can also

  The reaction product is discharged with the gas phase or liquid phase, preferably with the liquid phase.

  In the apparatus according to the invention, the reaction can be carried out in the pressure range of 0.2 to 40 MPa and in the temperature range of 0 to 350 °. In this case, the reaction is advantageously carried out under a catalyst which is homogeneously dissolved in the liquid phase.

  In the apparatus according to the invention, for example, oxidation, olefin epoxidation, hydroformylation, hydroamination, hydroaminomethylation, hydrocyanation, hydrocarboxyalkylation, amination, ammoxidation, oximation, hydrogenation can be carried out. .

  Advantageously, in the apparatus according to the invention, the catalyst is supplied with a liquid input and the reaction is carried out in homogeneous solution in the liquid product phase or starting material phase. Thus, for example, reactions such as the preparation of aldehydes and / or alcohols by hydroformylation of compounds with olefinic double bonds in the presence of cobalt or rhodium carbonyl with or without the addition of a ligand containing phosphorus. .

  In the following examples, the apparatus according to the present invention is described using the apparatus according to the present invention, but the present invention is not limited thereto.

Example 1
(Comparative example: Jet loop reactor H / D = 6)
In a jet loop reactor shown in FIG. 4a having a volume of 10 L, a height-diameter ratio (aspect ratio) of H / D = 6 and a nozzle above, 2- (hydroxymethyl) -acrylic acid methyl ester was dissolved in THF. At a concentration of 0.1 mol / L in the molar ratio S / C = 250 of the catalyst precursor [Rh (COD)] BF ₄ and substrate (S) to catalyst (C) and ligand (−)-2 , 3-bis [(2R, 5R) -2,5-dimethylphosphorano] -N-methylmaleimide (1,5-cyclooctadiene) rhodium (I) tetrafluoroborate, C ₂₅ H ₃₉ BF ₄ NO ₂ P ₂ Rh, (CatASium®-MN (S), Evonik Degussa GmbH) was mixed and reacted at 25 ° C. with a hydrogen pressure of 5 MPa and a residence time of 90 minutes. The product (2-hydroxymethylpropionic acid methyl ester) was obtained in a complete reaction with an enantiomeric excess of 95%. This reaction is sensitive to hydrogen partial pressure, where reduced pressure causes increased by-product formation and product dehydroxylation in the form of oligomerization of the substrate.

Example 2
(Invention)
In the apparatus according to the invention with two jet loop reactors arranged in parallel with an aspect ratio of 10 each having a reactor volume of 5 L each shown in FIG. 4 b, corresponding to the reaction conditions described for Example 1 The reaction was performed. The complete reaction was already obtained after 75 minutes in the device according to the invention, which contained a 95% enantiomeric excess. The hydrogen pressure could be reduced to 4 MPa and no significant by-product formation was observed.

  Both examples show that when the reaction is carried out according to the present invention in an apparatus having two parallel-connected jet loop reactors each having an aspect ratio of 10, compared to a single reactor with an aspect ratio of 6 It shows that the hydrogen partial pressure can be reduced at the same time that the speed is significantly increased.

  DESCRIPTION OF SYMBOLS 1 Jet nozzle, 2 Conduit, 3 Colliding plate, 4 Double jacket, 8 Liquid distributor of drive jet medium, 9 Gas chamber for fresh gas supply, 10 Circumferential chamber for change of heat transfer medium, 11 Liquid collection chamber for driving jet medium, A Supply section for driving jet medium, B Lead-out section for driving jet medium, Process connection section for heat transfer medium, D Process connection section for heat transfer medium, E Fresh gas introduction section

Claims (12)

  Continuous reaction of liquid and at least one other fluid, characterized in that it has at least two jet loop reactors connected in parallel to each other and one common external liquid circuit Device for letting.   The apparatus of claim 1, comprising one or more jet loop tube bundle reactors.   3. An apparatus according to claim 1 or 2, comprising at least one jet loop reactor and at least one jet loop tube bundle reactor.   4. An apparatus according to any one of claims 1 to 3, wherein in all reactors a nozzle is incorporated in the upper part of the reactor.   4. An apparatus according to any one of claims 1 to 3, wherein in all reactors a nozzle is incorporated in the lower part of the reactor.   4. A device according to claim 1, wherein at least one nozzle is incorporated in the lower part of the reactor and at least one nozzle is incorporated in the upper part of the reactor. .   Each nozzle has an outflow portion for the liquid, and the nozzle and the outflow portion are arranged on the diameter in relation to the internal liquid circulation path in the reactor, and the external liquid circulation path flows out of the nozzle. 7. The device according to claim 1, wherein the device is connected to a part.   8. A device as claimed in claim 1, wherein only one pump is arranged in the external liquid circuit.   The heat exchanger inside the reactor is omitted, and a heat exchanger is provided in the external liquid circulation path to exchange heat between the liquid guided in the external liquid circulation path and the heat transfer medium. 8. A device according to any one of the preceding claims.   A method for reacting a liquid with at least one second fluid, characterized in that the reaction is carried out in an apparatus according to any one of the preceding claims.   The method according to claim 10, wherein oxidation, olefin epoxidation, hydroformylation, hydroamination, hydroaminomethylation, hydrocyanation, hydrocarboxyalkylation, amination, ammoxidation, oximation, hydrogenation are performed in the apparatus. .   12. A process according to claim 11, wherein the compound having an olefinic double bond is reacted by hydroformylation with synthesis gas to an aldehyde and / or alcohol.

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